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Efficiently devising a strategy to synthesize titanium silicate-1 (TS-1) zeolite crystals with desired particle size and enriched framework titanium content for improved catalytic oxidation properties could be challenging. This study explores the incorporation of polyvinyl alcohol (PVA) and ammonium bicarbonate (NH4HCO3) as additives to decrease the particle size and increase the framework titanium content of TS-1, respectively. Powder X-ray diffraction (XRD), UV-vis absorption spectra, nitrogen adsorption–desorption, Fourier transform infrared (FT-IR) spectra, field-emission scanning electron microscopy (FESEM), and inductively coupled plasma (ICP) were used to characterize the TS-1 catalysts. The experimental results indicated that in the presence of NH4HCO3 and PVA (TS-1-S), the particle size and Si/Ti molar ratio of TS-1 were determined to be 170 nm and 43.55, respectively. Furthermore, the catalytic activity of the prepared catalysts in regard to the phenol hydroxylation with H2O2 has been evaluated. The TS-1-S sample showed a conversion of 29.52%, while the conversion of the conventional sample was 23.08%. This improvement can be attributed to the synergistic impact of reduced particle size and enriched framework titanium content. [ABSTRACT FROM AUTHOR]

Thin-film nanocomposite reverse osmosis (TFN-RO) membranes were fabricated in this study. Titanium silicate-1 (TS-1) was used as an additive during interfacial polymerization. Since nanoparticle dispersion in the membrane matrix is a significant challenge in fabricating high-performance membranes, polyvinyl alcohol/titanium silicate-1 (PVA/TS-1) composite with different PVA polymer dosage was prepared and used in TFN-RO membrane to provide better dispersion of the synthesized TS-1. As a result, the pure water flux increased by 39.5%, and the NaCl rejection improved from 95.03% to 99.1% at the optimum content of 0.1 wt.% (PVA) and 0.1 wt.% (TS-1). The antifouling properties of this membrane for bovine albumin serum (BSA) and humic acid (HA) were enhanced. Characterization of the morphologies of the membranes was investigated using AFM and FESEM. The measurement of water contact angle and zeta potential was accomplished to characterize the surface properties of the membranes. ATR-FTIR was used to study the chemical structure of the membranes. Following the introduction of the PVA/TS-1 composite, the TFN membranes became smoother, thinner, more hydrophilic, and negatively charged. Due to hydroxyl groups and less cross-linked structure of the top layer, water flux was higher. A smoother surface and more negative charges on the top layer also improved fouling resistance. [ABSTRACT FROM AUTHOR]

Thin-film composite polyamide (TFC-PA) membranes have recently been found to be highly capable of improving separation efficiency when subjected to surfactant-assisted interfacial polymerization (IP). There is a widespread belief that surfactants' ability to accelerate the diffusion of amine monomers, thereby promoting IP reactions, accounts for the improved performance. Through the IP and use of trimesoyl chloride (TMC) and m-phenylenediamine (MPD) on plasma-treated polyethylene (PE), this study investigates the utilization of anionic sodium dodecyl sulfate (SDS) surfactant for the development of TFC nanofiltration (NF) membranes. The alteration of the PA film structure induced by the various concentrations of SDS was thoroughly investigated using ATR–FTIR, water contact angle, zeta potential, FESEM, and AFM analyses. NF performance was then evaluated by testing four salt solutions, namely Na2SO4, MgSO4, MgCl2, and NaCl. Interestingly, the results revealed a notable influence of SDS micelles on the structure of the PA layer. Additionally, the introduction of SDS significantly affected the pure water flux during the NF process. Moreover, the rejection rates of salts were substantially enhanced upon increasing the concentration of SDS to 0.3 wt%. This study underscores the role of SDS in the preparation of NF membrane, highlighting its potential for improving membrane-based desalination prepared on hydrophobic supports. [ABSTRACT FROM AUTHOR]